Classification and Range
Australian walkingsticks are one of 2,000 species of tropical walkingsticks. They are in the family Bacteriidae, in the order Phasmatodea. Other common names for the Australian walkingstick include the giant spiny and Meckay's Specter walkingstick.
Australian walkingsticks are found in northern Australia and New Guinea.
Tropical forested regions.
Female Australian walkingsticks reach approximately 5 inches (12 cm) in length, while males are much smaller, attaining a length of about 4 inches (10 cm). These walkingsticks have elongated, oval-shaped heads covered with spines. They also have long antennae and chewing mouthparts for eating plant matter.
Females are light tan in coloration with long, thick bodies, and have a pair of non-functional wings. Males are dark brown in color and have a full set of functional wings. A male's forewings are dark in color, but the inside wings are often brightly colored and can be used as a warning to predators. When the wings are rapidly opened, the flash of color may startle a predator long enough for the male walkingstick to escape.
Adult life span is seven to 10 months.
IIn the wild: Certain species of eucalyptus
At the zoo: Blackberry bramble
There is no courtship between male and female Australian walkingsticks. The male is attracted by the female's scent. Once a female is located, he crawls onto her back, bends his abdomen around and mates with her. Sperm is transferred in a packet called the spermatophore. Mating can take hours, with males often "hanging out" on the female's back. Eggs are gray and tan in color. A female can lay up to 1,000 eggs in her lifetime.
Males do not have to be present for females to reproduce. Females are capable of parthenogenic (asexual) reproduction. If males are present and the female mates, eggs hatch within a few months. Parthenogenic eggs take longer to develop. Newly-hatched nymphs are approximately 0.8 inch (2 cm) in length.
The metamorphosis of the Australian walkingstick is incomplete (nymphs look similar to their parents). It takes approximately three to four months for a nymph to reach adult stage. During this time, Australian walkingsticks go through six or seven molts.
Australian walkingsticks are nocturnal, remaining mostly motionless during the day. Their enemies include birds and small mammals. If a predator approaches, walkingsticks will freeze in place, or sometimes even rock back and forth to mimic a twig shaking in the breeze. Their brown color and stick-like appearance also help them to look like a twig of the host plant and blend into their environment, camouflaging their presence from predators.
Female walkingsticks lay eggs in a number of interesting ways, depending on their species. Some randomly scatter their eggs, others conceal them, while others bury their eggs. Other species lay eggs in a more forceful way. As an example, one of the most prolific egg layers, the giant prickly walkingstick, can produce up to 1,000 eggs. When she's ready to lay, she quickly flexes the tip of her abdomen underneath her body, tossing the eggs below her head. Another species of walkingstick, Cyphocrania gigas, can eject her eggs almost 20 feet (6 m). For both species, spreading the eggs around this way reduces predation on their eggs and ensures food availability for their offspring!
Location at the Zoo
Amazing Australian walkingsticks are currently on view at Woodland Park Zoo's Bug World. You'll go "buggy" while viewing exciting seasonal displays that take you on a journey to different bioclimatic zones around the world. You may come face-to-face with recycling cockroaches, assassin bugs, web-spinning spiders or scuba diving beetles, to name only a few. The only way you'll find out which bugs you'll encounter is by visiting Bug World. Don't miss it!
Australian walkingsticks are not endangered. Human-caused changes in land use are escalating, and this affects the natural habitat required by walkingsticks and other animals for survival. Vast forests are being removed for timber or other paper products, and industrial emissions are polluting water and air resources. Additionally, habitat is rapidly converted by expanding human communities and agricultural needs. It's only a matter of time until many insect species populations will become severely reduced, or eliminated.
Humans need insects. Often unnoticed, walkingsticks and other insects are essential for maintaining the balance in nature and health of the living world. Here are only a few of the benefits insects provide:
- Bees, butterflies and other insects pollinate wild plants and our crops, ensuring the production of seeds and fruits required for the continued survival of plants and animals.
- Earwigs, beetles and other insect scavengers clean up the environment by consuming decaying plants and animals. Nutrients are recycled back into the soil, helping future generations of plants to grow.
- Many species of carnivorous beetles, ants and wasps eat other harmful insects that damage or destroy our crops and spread disease.
- Burrowing insects aerate and enrich the soil.
- Insects are a source of food for animals, including humans!
- Insects produce products used by people, including honey, beeswax, silk and dyes, to name only a few.
How You Can Help!
The effort to save animals and their habitat requires cooperation and support at the international, national, regional and individual levels. You can help in this cause. Join and become active in Woodland Park Zoo and other conservation organizations of your choice. To conserve habitat for sowbugs, pillbugs and other arthropods, reduce your use of pesticides and herbicides, and work to preserve vegetation in your neighborhood and in tropical regions.
Contact Woodland Park Zoo at firstname.lastname@example.org to find out how you can support conservation efforts at the zoo. Learn other ways you can help conserve wildlife and the habitats they require for survival by visiting our How You Can Help page.
Sources and Suggested Reading
Borror, Donald Joyce. 1974. A Field Guide to Insects: America North of Mexico (Petersen Field Guide Series). Houghton Mifflin Company, Boston, MA. 404 p.
Nuridsany, Claude & Marie Perennou. 1997. Microcosmos. Stewart, Tabori & Chang, New York, NY. 160 p.
Mound, Laurence. 1990. Insect (Eyewitness Book). Alfred A. Knopf, Inc., NY, NY. 64 p.